The present invention relates generally to computer systems, and more particularly to an event bounds adjustment system and method for pen-based computer systems.
Computers are becoming increasingly powerful, lightweight, and portable. The computing power of computers that once filled entire rooms is now residing on a desktop. Laptop, notebook, and sub-notebook computers are virtually as powerful as their desktop counterparts. Even smaller hand-held computers are now capable of computing tasks that required a much larger machine a few short years ago.
As a part of this trend, computerized personal organizers are becoming increasingly popular with a large segment of the population. Computerized personal organizers tend to be small, lightweight, and relatively inexpensive, and can perform such functions as keeping a calendar, an address book, a to-do list, etc. While many of these functions can also be provided in conventional computer systems, personal organizers are very well suited to the personal organization task due to their small size and portability. Personal organizers are available from many companies including Sharp and Casio of Japan.
A relatively new form of computer, the pen-based computer system, holds forth the promise of a marriage of the power of a general purpose computer with the functionality and small size of a personal organizer. An example of a pen-based computer system is the Newton.RTM. 120 pen-based computer made and marketed by Apple Computer, Inc. of Cupertino, Calif.
A pen-based computer system is typically a small, hand-held computer where the primary method for inputting data includes a "pen" or stylus. A pen-based computer system is commonly housed in a generally rectangular enclosure, and is provided with a dual-function display assembly that can serve as both an input device and an output device. When operating as an input device or "tablet", the display assembly senses the position of the tip of a stylus on the viewing screen and provides this positional information to the computer's central processing unit (CPU). Some display assemblies can also sense the pressure of the stylus on the screen to provide further information to the CPU. When operating as an output device, the display assembly presents computer-generated images on the screen.
The dual-function display assemblies of pen-based computer systems permit users to operate the computer as a computerized notepad, among other functions. For example, graphical images can be input into the pen-based computer by merely moving the stylus on the surface of the screen. As the CPU senses the position and movement of the stylus, it generates a corresponding image on the screen to create the illusion that the stylus is drawing the image directly upon the screen, i.e. that the stylus is "inking" an image on the screen. By "ink" it is meant that pixels on the screen are activated in such a manner that it appears that the stylus is leaving a trail of ink on the display assembly. With suitable recognition software, the "ink" can be recognized to input text, numerics, graphics, and other recognized information into the pen-based system.
Ideally, recognition software accurately recognizes the input text, numerics, graphics, and other information entered into the pen-based system. However, while constantly improving, current recognition software has yet to reach a level of sophistication and accuracy which allows data to be entered consistently without errors through a user scribbling (stylus entry) onto the surface of a display screen.
Take a common example involving the entry of date and/or time information. An sample date entry may consist of the user scribbling a specific character string "1/1/96" onto the dual-function display screen. In attempting to recognize this string, the recognition software must not only differentiate between the graphically similar (i.e. the characters have similar stroke characteristics) characters "1" and "/" which are contained in the specific string, but also between other similar characters such as "l", "7", "!", each of which may have a number of possible variations based on the user's handwriting style.
One reasonable attempt to optimize the performance of recognition software utilizes input fields designed for information of a predefined nature. The input field design may provide a formatted input field and/or limit the characters which the input field will accept. In the above numeric date entry example, the recognition software in conjunction with an appropriate input field will automatically eliminate characters such as "l" and "!" which are not allowable for numeric date entry. This will improve a given recognition software's accuracy, yet does not completely solve the problem.
Another approach provides the user a keyboard image which enables entry of the appropriate characters. While guaranteeing accuracy, utilizing the keyboard image with a stylus is a clumsy and time consuming method for data entry.
One of the most common usages of computerized personal organizers is the scheduling of events (meetings, appointments, to-do items, deadlines, scheduled phone calls, reoccurring meetings, etc.) on the user's computerized calendar. Typically these events have bounds which are defined by a variety of event parameters such as start time, stop time, start date, stop date, event duration(stop time minus start time), and reoccurrence duration (roughly stop date minus start date). Accordingly, it is particularly important that developers of computerized personal organizers provide a data entry system and method which allows these event parameters to be conveniently yet accurately entered.
In addition to the base requirement of providing accurate information to the computer system, whatever data entry system and method is chosen must satisfy the natural requirements of pen-based personal organizers. For example, as will be appreciated by those skilled in the art, an ongoing challenge in the field of computerized personal organizers is providing a suitable mechanism for entering meaningful input through what are relatively small display screens.